Posted 31 Oct 2015 Hi guys, newbie programmer needs help with your expertise. From the attached logic,I have 2 identical outputs to control (image shows 1) with a switch it changes modes where one mode outputs are independent and the other dependent of each other. in the dependent mode, the outputs control are independent up until B3:0/2 and B3:0/4 (Inj01 and Inj02 bits) are toggled. What i need next is a sort of flip flop where the first output O:0/1 goes first until a 1st transducer reaches a given set point disabling bit B3:0/2. before B3:0/2 gets disabled by 1st transducer , bit B3:0/4 becomes active waiting to enable 2nd output O:0/3 and vice verse when 2nd output gets disable by a 2nd transducer. i really would appreciate if somebody point me in the right direction. I couldn't come up with a simple solution. I hope i explained myself Thanks in advance Share this post Link to post Share on other sites
Posted 31 Oct 2015 (edited) Your description is not clear to me. Your rung 4 as shown will only energize O:0/1 if the Power is ON (B3:0/0), Inj01 (B3:0/2) is ON and EITHER Inj02 (B3:0/4) is OFF OR Switch Mode 02 (I:0/5) is ON - three of the other instructions you indicate as 'Enabling Instructions' have no real effect. State the relationship between inputs and outputs as a series of steps. Maybe that will help Edited 31 Oct 2015 by b_carlton Share this post Link to post Share on other sites
Posted 31 Oct 2015 I am sorry, my fault. dismiss the instructions inside the box on rung 4. that's the part i am trying to fix and that's just some of the logic i tried. attached find the whole logic removing the instructions in the box: Basically the logic goes like this: Rung 0 I:0/0 button latches bit B3:0/0 (power On) Rung 1 I:0/2 button toggles bit B3:0/1 Rung 2 latches output O:0/0 (power clamp 01) Rung 3 power clamp closes activating reeds I:0/4 latching bit B3:0/2 (Inj01) Rung 4 bit B3:0/2 when active splits into: Mode 1 (switch) latches output O:0/1 (shut Off Ball valve Inj01) which is dependent on O:0/3 (shut off ball valve 02) to complete it's cycle and vice verse (flip flop). Mode 2 (switch) by pass the " flip flop" logic parallel to it (blank line) and makes the 2 controlled outputs O:0/1&O:0/3 independent to operate of each other. Rung 5-8 completes the logic of the second identical control to "flip flop"Notes: I:0/3 and I:0/7 are pressure transducers that unlatch each of the controlled outputs O:0/0-O:0/1 and output O:0/2-O:0/3 when a given set point is reached for every leg of the control. the shown logic does everything i need but the part where i need the switch open (Mode 1) to make independent each of the legs (blank line parallel to switch closed in Mode 2 in rungs 04 and 08). Described as process: start push button 01 to inject mold 01. mold 01 clamps activating reed switches 01 Reed switches 01 in clamp enable ball valve 01 to start Injection 01 while injection 01 happens, mold 02 cycle starts by pressing button 02 mold 02 clamps activating reed switches 02 ball valve 02 waits for injection cycle 01 to complete when mold 01 reaches a pressure set point, it unlatches ball valve 01 stoping Injection and clamp 01. Ball valve 02 opens starting Injection 02 same sequence keeps repeating between Injection 01 and 02i hopes it makes better sense now, thanks for taking the time to look at it. MICRO02 10-17-2015.pdf Share this post Link to post Share on other sites
Posted 1 Nov 2015 I think I understand but let me restate it to be sure. The Start button is pressed which enables operation until the Stop button is pressed. Now the operation for just one section - The mold's Start button is pressed The clamp activates until the clamp reed switch is made The injection ball valve then activates until the pressure transducer is made Then both the injection and clamp turn off until the Start button is pressed again You have two of these sections. In one 'mode' either section operates independently of the other. In the other 'mode' only one 'injection' output may be on at any time. If this is so I would modify rungs 3, 4, 7 and 8. Rung 3 add three parallel contacts - XIO B3:0/4, XIC B3:0/2, XIC I:0/5 Rung 4 remove XIC I:0/5 and, of course, the empty branch. Rung 7 add three parallel contacts - XIO B3:0/2, XIC B3:0/4, XIC I:0/5 Rung 8 remove the XIC I:0/5 and, of course, the empty branch Share this post Link to post Share on other sites
Posted 1 Nov 2015 Your understanding is correct. I followed your advice, the independent control part works when I:0/5 switch is off but the bit B3:0/2 doesn't manage to latch and stays blinking when the I:0/5 switch is on for the dependent control part. the parallel XIC B3:0/2 is the only part of the rung left to set the coil and overrides with the coil bit. see the attached logic showing what I did, I hope that's what you meant. Thanks MICRO02 11-01-2015.pdf Share this post Link to post Share on other sites
Posted 1 Nov 2015 I think you misread my reply - remember - XIC = --] [--, XIO = --]\[-- In rung 3 change XIC B3:0/4 to XIO B3:0/4 , also change XIO B3:0/2 to XIC B3:0/2 (actually I'm now not sure if this 'latch' of B3:0/2 is even necessary, you can try leaving it out) In rung 7 change XIC B3:0/2 to XIO B3:0/2, also change XIO B3:0/4 to XIC B3:0/4 (again you may be able to delete this contact) 1 person likes this Share this post Link to post Share on other sites
Posted 1 Nov 2015 That did it, Thank You! I tried that before in the output rungs instead without the latch but 2nd output control cancelled first one without waiting for its completion. I was thinking some other instruction type might be needed. I am not very experienced as I mentioned but I am trying to learn at least the basic to do this kind of logic. I have not fully explored the forum, is there any specific section that you might suggest to look at? some links with examples of basic commands? I really appreciate your help, thanks for all your time. Share this post Link to post Share on other sites
Posted 1 Nov 2015 (edited) I think careful description of the operation is the most critical part of programming, even before the first rung is created. When I begin I don't even consider which PLC will be used (we work with several). If I can't clearly describe the sequence then it is useless to begin using the programming software. In this particular case, the description that one or the other injection process may begin but not both (for the dependent mode of operation) is the key. Only when the description is complete is it proper to consider which instruction tools the chosen PLC has to offer. Most current PLCs have a sufficiently complete array of instructions to make any logic sequence able to be implemented in code. (Oh, an I learned basic PLC/ladder programming before there was an Internet to offer help, just books and trial and error.) Edited 1 Nov 2015 by b_carlton Share this post Link to post Share on other sites
